Panoramic sight



March '20, 71951 G. RATTRAY PANORAMIC SIGHT 4 Sheets-Sheet 1 Filed June 13, 1946 /64 Be 055 E Hutcruy March 20, 1951 cs. RATTRAY PANORAMIC SIGHT 4 Sheets-Sheet 3 Filed June 13, 1946 62 I3 2 cm 2 Eulficrtp G- RATTRAY PANORAMIC SIGHT March 20, 1951 4 Sheets-Sheet 4 Filed June is, 1946 Patented Mar. 20, 1951 UNITED S-TAT-E.1S PATENT OFFICE *PANOitAMIC SIGHT GeorgeRattray, Mineola, N. Y., assignor to Mer- .-genthalerlLinotype Company, a corporation of 1 New York Application June 13, 1946, Serial No.:676;52?7

11 Claims. i invention; relates to a panoramic sight wot-general utility but intended more specifically for useinythe layingpfa gun mountcd upon the turret ofqaxqtank or other armored vehicle.

.It .isqan object -of the invention to provide a panoramic sight that'may be inserted intoits mount from'it-he interior of the turret.

. Anothernobject is; to;provide a Sight of the type mentioned wherein. adjustment of the line of. sight in elevation 18,- effected by rotation of ;the entrance prismfrom a position closely adjjflflfihbrthB ocular .and"by-,.a Simple positively- :aotingj mechanism completely enclosed within the. telescope. tube.

Another object is to provide apanoramic weight operable to: rotate its line of sightthrough 360 1 of azimuth -and strongly constructed so that. theport-ion projecting from the turret may ,sllfitainapowerful blows as from tree limbs, 'IBIlemy attacks, -etc., wvit-hout derangement and.

without injury to the personnel Within the turret.

I :More specifically, the 1 immediately foregoing object is attained by :ruggedpivotjoints that provide support along the pivot axes; on" each side of the instrument;

A further object istthe' provision of'a panoramic-sight having compact, completely enclosed adjusting and indicating gmec'hanism adjacent the ocular at :its lower end to rotate the line of sight .thereotpin azimuth and elevation.

Anotheraxobjectis theprovision of a sightas in the preceding paragraph wherein the adjust- .ingand elevating mechanism includes means to maintain'gerect ;the,;field of view in said ocular forv all azimuthal positions of the'line of sight.

. A still further obj eot is to provide. a universal gimbal. mount ,for :a telescope of the type-aforesaid that has closely interfitting surfaces forall angular :positionsof the telescopenrelatively to the 'turret,;wl'1;ereby the entrance of foreign substances irom without the turretiis prevented.

Another object is to provide a telescope and universal mount. having =three mutually normal pivot .axesethe intermediate one :of which is maintained parallel to :the gun bore axis, to- 1 gether-with-means to pivotwsaid telescope about said axes to bring r-said telescope into the ventical despite inclination of 'the turret on .which it is mounted.

Other objects and advantages will become apparent-as the description proceeds.

In the drawings:

Figure l is an elevational view of the lower end of the sight showingtthe azimuth adjust- 'ment, the leveling connections and the-mount,

the latter being shown in. section on. a .plane substantially as indicatedby the line l-;|,.Fig-

ure. 3.

Figure lais an elevation corresponding to Figure 1, showing the top, portion =-of the tube positioned exteriorly of the tank, the upper portion being sectioned to show the mount and operating connections for the entrance prism.

Figur 2 ;is across section through the central longitudinal axis of-the lower portion of the instrument, :asindicated by the line 22, Figure 1. 1 Figure 2a is a view corresponding to Figure 2 showing in cross section the upper portion of the sight, as indicated by the line 2aF--2a, Fig- ..-Figure 3 isa cross section taken upon a plane :indicated bythe line .3- 3, Figural, and :illus- 'trating the telescope mount including the fore @sameplane as Figure 2 and showing the propjecting flange'ior the sight, the flexible skirt .to exclud the entranceof moisturehand dust, .and the key-way for locating the sight indeffinite predetermined position within its mount.

'jFigure 8 isjasectional -.view through. a tank turrethaving mysight appliedthereto and taken in a vertical plane parallel to the gun bore.

Figure 9 is a view to an enlarged :scale of a portionwoi Figure 2 to show clearly the mechanism zforcefiecting tilting of the entrance prism.

Referring gin detail to the drawings, 1 identifies an upper tube section of the telesoopeand r2, a:jlowerr tube section. The .t-wosections are .connected in alignmentand l-ior relative rotation about their common central axis by a joint that, as shown in Figures 2 and 2a, comprises a coupling 3 having a counterbored threaded connection 4 with section I and having a circular flange 5, Figure 2, fitting a channel 6 in the end of section 2. Both flange and channel are concentric of the common axis I of the sections I and 2 which is also the optical axis of the instrument.

The upper end of section I is closed by a flanged cap 8 threadedly engaging the section. The wall of section I adjacent cap 8 is flanged as at 9 to' receive a transparent pane I9 h-ld in place by a bezel II. The upper end of I also has a pair of aligned openings I2 and I3 defining an axis diametrical of the tube section and parallel to pane Ill. Bearing pins I4 and i are threaded into these openings and have reduced ends having a smooth fit in hol;s in a frame I5. A 45 entrance prism I! is fixed in frame it for pivotalrmovement about the axis I8 lying in the reflecting surface of ii. Frame I6 is urged into clockwise rotation, as seen in Figure 2a, by a spring. i9 engaged at the other end with an apertured screw 2i threaded into the tube wall. A second lug 22 on frame 15 has pivoted connection with a push rod 23 adjacent one wall of section I and that terminates in a flattened end at the joint between the two sections. Rod 23 is guided for axial translation by a smooth fit in ap;rtures formed in lugs 24 and 25 integral with section I. The rod also passes through an aperture formed in a retaining flange 26 for'a lens 21 and an aperture formed in a retaining flange 28 for a-second lens 29. By this construction, prism I? is rocked about its axis I8 to deflect the line of sight vertically as rod 23 is translated by means subsequently described.

' From Figure 2 itwill be noted that a sleeve 30 is positioned within section 2 and has a smooth fit therewith at its top, as indicated at 3I. This sleeve is threaded at its upper end to receive a threaded collar 33 seated against a shoulder 34 formed by the counterbore of coupling 3, to thereby hold the two tube sections together. A collar 35 is threaded into the lower end of tube section I and acts as an abutment to limit the downward movement of rod 23 when the sec- 'tions are disconnected. By the foregoing conthreaded,-as indicated at 36, Figure 2, to receive the flange coupling 31 forming the upper portion of an indicator housing or casing, indicated generally by the numeral 38. The lower section 39 of housing 38 is generally cylindrical with a reduced lower end and has its upper end formed with a flange 40 mating with the flange of coupling 31. As seen at Figure 4, the two flanges have six equally spaced holes through which connecting bolts or screws may be passed. The

two flanges may thus be secured together in various rotational relations to accommodate diifer- "ent installations.

The lower end of sleeve 39 is reduced and threaded as indicated at M. A cup-shaped indicator 42 fits on the aforesaid end of sleeve 39, and is held in position by a bevel sun gear 43 threaded on said sleeve and forming one side of a differential whose construction and function Coupling 3, of course, ro-

. v 4. will be subsequently described. As shown at Figure 1, the periphery of dial 42 is graduated in 64 equal units of mils each, and moves opposite a window 44 covered by a glass 45 held in place by bezel 46. An index 41 is formed upon the beveled edge of window 44 and against which the graduations on dial 42 are read. The indicator 42 is formed with an internally-threaded flange 48 within which one end of a tube portion 49 is threaded. This tube portion is formed integrally with, or has attached thereto, a worm gear 59 and, at its lower end rotatably fits a guiding flange 5| upstanding from thebase of section 39. A shaft 52, Figures 2 and 5 is journaled in bearings provided by aligned bores in tangential projections 53 and 54 of housing section 39. This shaft has a worm 55 in mesh with gear 59 and projects, at both ends from the housing. Operating knobs 5B and 51 are attached to the respective ends of shaft 52. Knob 51 has a scale 58 formed about a smooth portion of its periphery. This scale may be graduated in 100 units and geared to rotate 64 times for each complete 360 rotation of gear 50 and dial 42, whereby rotation of the line of sight may be read to the nearest mil. The scale 58 is read opposite an indicator 59 which, as seen in Figure 1, may comprise an apertured plate screwed to projection 54 and carrying a transparent plate having an indicator line 69 scribed on its side closely adjacent the scale. A gunners scale BI is provided in the form of a knurled band having a snug fit on a turned bearing portion of projection 54, concentric of shaft 52 and having a scale similar to or identical withscale 58. The two scales are contiguous and scale BI is also readable against line 69. .By the use of scale 6| an arbitrarily selected base line may be established as for firing at invisible targets, in the manner well known in the art.

By the foregoing construction, as shaft 52' is turned, corresponding rotation as a unit is effected for portion 49, dial 42, sleeve 30, coupling 3, tube section I and prism H, to thereby rotate the line of sight in azimuth through precise and accurately measurable angles.

From lens 29, the field of view is projected to a lens 62 held in position by a sleeve 63 and retainer ring 64, within a counterbore inthe lower end of a tube 65. Tube 65 has a smooth fit at its lower end within sleeve 30, as indicated at 32. A little above bearing portion 32, sleeve 65 is reduced in diameter to provide an annular space between itself and sleeve 39. A second sleeve II has its lower end fitting the aforesaid annular space to provide concentric bearing surfaces for all three sleeves 39, II and 55, as indicated at I2, Figure 2. Above bearing portion I2, sleeve 65 has its outer diameter reduced to provide a clearance between itself and sleeve II until at its top, it is again enlarged, to provide another bearing portion I3 between itself and sleeve II. Sleeve II is internally enlarged between bearing portions I2 and I3, to afford additional clearance with sleeve 65. Sleeve 39 is also enlarged internally between portion '72 until it is again reduced at its top to provide a bearing surface I4 for sleeve II.

Sleeve 65 has a carrier 61 fitting its upper end, within which a dove prism 66 is mounted. Rotation of sleeve 65 at one-half the speed of r0- tation of the line of sight, is effected by a differential, of which one sun gear 43 has been described. The other sun gear 68 is fixed to housing section 39 as by being threaded into flange per surface ofJ-dial 4'2.

. motion.

fit within bearing holes in sleeve! I. structi'on, rotation of knob-84 acts to translate v.5 Iyas clearly :shown .upon Figure 2. The lower end of tube -65 has planetarygears' B9 and I pivot- -ed upon its lower .end, each in mesh with sun gears 43: andc68. In this manner, prism 66 is rotatedcat half the speed of rotation of sleeve 2 30,.to thereby maintain erect the field of view,

inthe manner well known in the art.

"The rod'23 and the mannerin which its trans- .lationefiects pivotal m'ovement of. prism II about axis 18, have been described. The foot of rod 23 rides on sand abuts the square-cut end of sleeve .1 I so that translation of sleeve I I effects pivotal movement of prism I1. v

A relatively short thin sleeve portion l l' is interposed between sleeve 30 and tube :section 2,

as more iclea'rlyshown at Figured The lower-end of sleeve I4:is 'outwardlyrfianged at I5. An internal shoulder of a threaded ring-I6 is held in contact with flange- 7.5, by :a'retainer ring '1! that may be threaded into ring IS. The sleeve M and its flange I are thus rotatable relatively to ring- 16, while axial movement of the flange relatively to the ring is prevented. Ring 55 has a -.numberof axially-extending pins, such as I8 each pin being slidably accommodated within a corresponding bore formed in the end of section 2 whereby the ring is limited to translation along axis :I..

An'intern'ally threaded sleeve or collar I9 has an axial dimension 'ior'a smooth fit between the lowerfinished surface of coupling-3T and the up- The sleeve threadedly engages ring 16 and has an-external flange 8!! to which a bevel gear -8I is attached in a position concentric of axis I. A shaft'82 is ,iournaled withina bearing formed in the wall of housing 39, and

:carriesa bevel pinion 83 in m sh w t ear -8I. -A knob 84 on shaft 82 enables rotation of gear BI and sleeve 19, to thereby vertically transsleeve ll androd 23 and to pivot prism I! to deflect the line of sight in elevation. Since rotation of sleeve II relatively to rod 23 does not affeet the adjustment of prism II about axis I8, pins 85 and 86-are not required to have a snug fit 'throu'ghthe elongated slots in sleeve 35. In other rdspanv p ay of s eeves I and M ab ut axis has no efiect upon the adjustment of the line of sight, either in azimuth or elevation.

From lens 82, the field of view passes to Amici prism IiI, carried bya frame 88 in a-reduced lower extension of housing section 39. The exit portion 89 of this extension has an ocular 90 comprising a reticle SI at the focal plane of'the lens-62,- a conventional eye-piece assembly 92 and rubber guard '93. -A cross-leveling bubble tube level 9 E, Figure l, is mounted between lugs depending from the bottom wall of housing section 39. One end of the level housing is closed by a threaded -plug*95 while the other end communicates with a lamp housing 96 mounted in lugfil" coaxially of "the level. A small incandescent bulb is mounted within housing -96 and lengths oi Lucite or other light-conducting medium 98, "99 and IE0 extend from openings in the housing to terminate adjacent window 44, indicator 59 and reticleSI, respectively, whereby to illuminate the various dial and indicator portions "of the instrument. Rod toi -extends "through. a hole in extension to a position adjacent the periphery ofxreticle 9| and is held in nposition by a-fianged ring IDI, secured to extension 89, as shown iniEligure l. A second fore and aft level I02 is indicated in Figure 5 with its axisatrightangles to level. This level is-carriedin the same manner as level 94 and :has one end in communication with housing 95.

Thus one lamp serves to illuminate both levels :as well as the azimuth scales-and reticle.

The ."mounting for the sight .is shown in detail linEigures 1 to 3, inclusive, '7 and 8, wherein T indicates the top of the tank turret having therein a circular opening A,'Figure '7. A 'closure ring 103 has a projection 1 I14 fitting opening A,aas well as a flange provided with an upwardlyextending, frusto-conical projection I115 aifording protection of the exterior portions of the telescope against injury by blows and enemy fire. Screws I05 secure ring I 03 to the turret, a gasket m1 being provided between the two to afford a weather-tight joint.

Ring I03 has -a square'opening I08 having two cpposite side edges square cut as indicated at I09, Figure l, andthe other two edges concave :over their top halves as at I'Iil, Figure 2 to form the surface of acylinder concentric about an axis through point III, normal to the plane of the figure. As seen atFigures l and 3, a pairofpivot pins I I3 and I it are mounted in aligned bores at diametrically opposite sides of ring I03, to define an axis that is parallel to the axis of elevation of the gun, as will be subsequently described.

Each pin may be retained'in position by respective plugs I I5 and IIBhaving a reduced threaded end engaging an axial threaded hole in the pin. Eachplug fitsa-counterbore of its aperture in ring I63 whereby; when the pin and plug are screwed together axial movement of thepin is prevented.

A gimbal ring I I2 has square-cut and convex sides to fit opening I08, as clearly shown in Figures l and'2. "This ring has aligned openings to receive the outer races of anti-friction bearings I1 I and H8. The projecting ends of pins H3 and I I4 fit the inner'races of these bearingsand thus act topivot gimbal ring II2 for movement about an axis I I2, Figure 3, passing through pivot point II I. Because of'the'mating cylindricalsurfaces I I9, the small clearance between rings I83 and I I2=:remains constant and affords sub-stanitially no'space for the entrance of dirtand moisture "The inner sides of 'ringI'I2 opposite each of the souarecut outer sides, are formed as concave cylindrical surfaces concentric of an axis through point II I, normal to the plane of Figure 1. The other-two sides are flat, as indicated at I20. Gimbal ring I I2 has pivot pins I22 and I23 fixed in opposite alignedholes therein to define an axis I24 at right angles to axis I I9. These pins projectinto, and fit,'the innerraces of bearings I25 and i 26 carried by a second gimbal ring I2I. Ring I2I has two opposite sides flat to fit between the fiat sides of ring I I2. Its other two sides are formed externally as cylindrical surfaces about axis I24, as indicated at I21; Figure l, to have a smooth fit within the inner cylindrical sides of ring -I I2 whereby it may freely pivot about axis I24 relatively to ring I I2, without altering the relatively close fit between the two.

Ring I2I has aligned openings in which are fixed pivot pins I28 and I29 to define an axis through point II I normal toaxis 124. This axis and sleeve I32 lie in closely adjacent parallel planes normal to the axis of pins I28 and I29. Likewise, from Figure 2, it will be noted that sleeve I32 is enlarged to form convex portions of the surface of a cylinder about the axis of pins I28 and I29 which closely and smoothly fit between the concave inner cylindrical surfaces of ring I2I also concentric of the axis of pins I28 and I29. The three gimbal axes thus defined by the respective pairs of pins H3, H4, I22, I23 and I28, I29, are concurrent at point III.

Sleeve I32 has an internal bore within which enlarged bearing portions I33 and I34 of tube section 2 closely fit. Since no portion of the coupling 3 and tube section I has a transverse dimension greater than the diameter of the aforesaid bearing portions, the telescope may be inserted into its mount from within the turret. The lower end of sleeve I32, has threads I35 on its lower end, adapted to be engaged by the internal threads formed in the upper counterbored end of a retainer I36. This counterbore forms shoulder adapted to engage the external flange I31, Figures 2 and 7, of tube section 2. A knurled flanged enlargement I38 integral with retainer I36 is provided to facilitate rotation thereof. Retainer I36 has a smooth fit on the portion of section 2 below flange I31 and when turned home upon sleeve I32, acts to firmly hold the telescope within said sleeve. Referring to Figure 7, it will be noted that sleeve I 32 and flange I31, have an interfitting projection and depression, as at I39 whereby the telescope may be located in a precise azimuthal position within its mount.

The top of sleeve I32 is flanged and threaded to receive a ring I40, 2. flexible boot I4! has its lower edge secured to ring I03, just inside projection I05 as by circumferentially-spaced screws I43. The upper edge of the boot is attached by clamping between ring I40 and a retainer ring I42 held to ring I40 by screws I44. This boot effectively keeps foreign substances from lodgement between the relatively moving parts of the mount. The axis I24 defined by pivots I22 and I23, is the cross-leveling axis of the mount and, in accordance with usual procedure, is maintained r.

parallel with the axis of the gun bore. This parallelism is automatically preserved in the present invention by a linkage connection between ring I I2 and the gun. This linkage is shown upon Figure 8 which also shows the gun G having its breech portion within turret T and rotatable as a unit with the turret. The gun is carried on the turret by trunnions defining an elevation axis I45 normal to the plane of the paper in Figure 8. A bracket I46 is secured to the gun and is pivotally connected with an adjustable-length link I41 on an axis I48 parallel to axis I45 and spaced therefrom a predetermined distance. The link I 41 comprises two aligned sections I 49 and I56, connected by a turnbuckle I5! so that the effective length of the link may be varied.

A shaft I52 is journaled in a pair of brackets afiixed to the top of the turret. A crank arm I53 is secured to shaft I52 and is pivoted at its end I to the other end of link I41, as at I54. The con- 8 nections are such that the distance I45-I48 is equal and parallel to the distance I52--I54. The shaft I52 extends to the right hand side of the gun, where it has secured thereto a second lever arm I55. The outer end of lever I55 is pivoted on an axis I56t0 a second adjustable link I51 having its other end pivoted at I58 to a lever arm I59 which, as best shown upon Figure 1, is fixed by screws I60, to one side of ring H2. The link I51 is adjustable in effective length in the same manner as link I41 and the connections and dimensions are such that the distance I52-I56 is equal and parallel to the distance III-458.

The gun is shown upon Figure 8 as at zero quadrant elevation. described, and the rotational position of ring I03 with relation to the turret, are such that the axis I24 determined by pivot pins I22 and I23 is parallel to the gun bore axis. At this time, with the indicator dial 42 at zero indication, the line of sight lies in a plane parallel to the vertical plane through the bore axis by reason of the interengaging projection and recess I39. Hence, ring H2 is rotated synchronously with the gun as the latter is elevated or depressed and axis I24 is at all times parallel to the bore axis.

By reason of pivot pins I22, I23 and I28, I29, the sight is mounted for universal pivotal movement about pivot center III and in normal operation, is brought to a true vertical position. This adjustment is eifected by a connection between the lower end of housing section 39 and the turret. Referring to Figures 1, 2 and 8, it will be noted that the aforesaid section 39 terminates in a flange I6I 'and is connected by screws I62 with a mating flange integral with a stud I63 having a reduced threaded end I64. A collar I65 fits stud I63 and is adapted to be held thereon by a nut I66. Co'lar I65 has forked projections I61 and I68 extending therefrom each adapted to form one section of a pair of universal joint connections. The mating section of I61 is identified at I69 and is fixed to one end of a link I10 having its other end connected through a universal joint I1I whose final section is attached to the turret wall.- The link I10 consists of two oppositely threaded aligned parts I12 and I13 connected in alignment by a turnbuckle member The mating section of projection I68 is carried at one end of a second adjustable link I15 identical in construction with I10, and connected to the turret wall at I16, through a universal joint I11. Preferably, but not necessarily, the lines of action of links I10 and I15 are substantially at right angles to each other.

Assuming that the link connections between the gun and telescope mount have been effected and adjusted as described in connection with Figure 8, the telescope is placed in position by sliding sections I and 2- upwardly from within the turret, through telescope mounting sleeve I32, until projections I39 interengage. At the same time retainer I36 is turned up on threads I35 of sleeve l 32 to thereby firmly hold the telescope in position. When a visible target is selected for engagement by the tank commander, the indicator dial is adjusted to zero as shown in Figure l. The gun is elevated to the angle corresponding to the predetermined range of the target. This movement acts through the linkage shown in Figure 8, to pivot ring II2 about the axis II9 determined by pivot pins H3 and H4. It will be remembered that this axis is parallel to the gun trunnion axis and because of the parallelogram The link connections just linkages the axis l fl determined by pins I22 and I23, elevates synchronously with the gun and remains parallel to the'boreaxis. The turret is then rotated until the target is pickedup in the line of sight and, apart from minor adjustments for windage, drift;etc., the'gun is then properly aimed in case the tank position is truly horizontal.

In nearly all cases,-however, the tankwill have components of "tilt both in the vertical plane through-the trunnion axis, 'and in'the vertical plane through the bore axis. The first 'component will introduce errors bothin azimuth and elevation, the second-in elevation only. When such tilt components arepresent, they will result in-departure of one or bothlevels 94 and I02 from centralized position. The gunner then ad: justs the turnbuckles of thelinks llfl and H5 until both levels are again centralized and the optical axis of the telescopei's vertical. The component movements necessary to thus render the telescope vertical take place about mutually per-' pendicular axes, namely, the axis l24elevated tothe angle of gun elevationand parallel to the bore axis, and the axis determinedby pivot pins I28 and I29.

The first component of ti t abovementioned, namely, trunnion tilt, causesthe bore axis of the elevated gun to traverse a'portion of the surface-of a cone having its axis horizontal, and thus deflects the gun bore from correct position, both by a changein azimuth and adecreasein elevation. When the/telescope is brought to the vertical by cross-leveling about axis I24, the line 7 of; sight traverses the surface of a cone about anaxis parallel to 'thebore axis and is deflected in azimuth and depressed in elevation relatively to the bore axis by angular values that are equal to the aforesaid deflections of the gun from its' rotated as a unit to restore the line of sight to I the target the azimuth error is fullycorrected. The line of'sight maybe moved in elevation the slight amount necessary to pace it upon the target, by adjustment of knob 84.

In firing upon an invisible target, the range and" azimuth at thegun, relatively to a visible aiming point are determined. The gun is elevated to the quadrant angle for that range'and theturret is rotated until, with the telescope vertical, the cross wires intersect the aiming point. The knob 51 is rotated to rotate the line of sight in the opposite direction to the invisible target until the dial '42 and scale 58 are moved from zero to indicate the predetermined azimuth of the target from the aiming point. The turret is then rotated until the line of sight is again upon the aiming point. Cross-leveling is effected as previously described, and a final azimuth adjustment of the turret is effected. When the sight is vertical and on the aiming point,'firing is'begun.

The sight may also be usedtodetermine the azimuth angle at the tank between and two visible'points. Since the initial and final readings are taken in each case with the optical axis of the telescope in vertical position, the scale reading or difference in readings, gives the true angle between the points measured in a' horizontal plane.

I have thus provided a: panoramic sight that is rugged, highly accurate, rapid in operation and versatile in operation, while I'have shown the form now preferred, alterations, modifications and substitutions of equivalents will occur to those skilled in the art after a study of the present disclosure. Hence I donot wish to be limited to the precise details of construction shown and I desire to reserve all such changes as fairly fall within the scope of the sub-joined claims.

Having now fully disclosed the invention, what I claim and desire to secure by Letters Patent is: 1. In a panoramic telescope, upper and lower tube sections interconnected in end-to-end relation for relative rotation about their common axis only, an entrance prism carried by the upper end of said upper section for pivotal movement about a normally horizontal axis, and deflecting rays incident thereon alongthe axis of said sections, a housing carried by the lower end of said lower section, first and-second sleeves within said lower section coaxial therewith, an indicator dial in saidhousing and fixed to the lower end of said first sleeve concentric of said common axis, first manually operable means carried by said housingand connected to rotatesaid indicator and thereby said first sleeve, second manually operable means carried-in-said housing to axially translate said second sleeve and including an internally threaded third sleeve rotatably mounted coaxially of said tube sections by and between said housing and 'dial,a positive driving connection between'said first sleeve and upper tube section, a push rod translatable on and along said upper section and engaging the square-cut upper end of said second sleeve, and means operated by said rod to rotate said prism'in-response to trans lation of said second sleeve and second manually operable means carried by said housing and operable to rotatesaid third sleeve and thereby pivot said entrance prism about its normally horizontal axis;

2. In a panoramic telescope, a normally-vertical tube, having 'an entrance reflector pivotal within its upper end for pivotal movement about mutually normal azimuth and elevation axes, a

housing secured to the lower end of said tube and having an annular top wall, means to rotate said reflector about said azimuth axis including a first sleeve fixed with said reflector and rotatable within and coaxially of said tube, and a dial in said housing fixed to said .first sleeve coaxial therewith, and meansto rotate said reflector about said elevation axis, including a second sleeve limited to translation within and axially of said first sleeve, a threaded ring in said housing connected with said second sleeve said ring being limited to rotation coaxially of said sleeve, a third rotatable sleeve threadedly engaging said ringand fitting between said dial and the top wall of said housing," whereby rotation of said third sleeve axially moves said ring and second sleeve, means responsive to axial movement of said second sleeve to pivot said reflector about its elevation axis and means responsive to axial movement of said second'sleeve to pivot said enj trance reflector about its normally horizontal axis.

3. A periscopic telescope comprising a normal ly vertical telescope tube defining a first axis, an entrance prism, tubular means mounting said entrance prism on said tube for rotation about said first axis and tilting about a second axis normal to said first axis, said second axis lying in the reflecting surface of said prism, a housing secured to the lower end of said tube and having a top formed with a plane lower surface normal tosaid first axis, a rotatable indicator dial in said housing concentric of said first axis and having a plane upper surface spaced below andparallel to the plane lower surface of said top, a sleeve having a smooth fit between said plane surfaces, and concentric of said first axis, said tubular means connecting said dial and prism for rotation as a unit about said first axis, a connection between said sleeve and prism to tilt said prism about said second axis in response to rotation of said sleeve, first manually operable means carried by said housing to rotate said dial and prism and second manually operable means carried by said housing to rotate said sleeve and thereby tilt said prism.

4. In a periscopic sight for a gun mounted for elevation upon an unstable platform rotatable in train, upper and lower aligned tube sections, connected for relative rotation, optical means carried by said tubes and adapted to deflect a line of sight 90 downwardly through said section, thence 90 into an ocular carried by a housing upon the lower end of said lower section, a mounting plate fixed to said platform and having a generally rectangular opening therein, a first gimbal ring closely fitting said opening and pivoted therein upon a first axis parallel to the elevation axis of said gun, a second generally rectangular gimbal ring closely fitting said first ring and pivoted therein on a second axis normal to said first axis, a mounting sleeve closely fitting'said second ring and pivoted therein on a third axis normal to said second axis, the interfitting surfaces of said plate, rings and sleeve being formed as portions'oi surfaces of revolution about their respective axes, means connecting said gun and first ring to maintain said second axis parallel to the gun bore axis, and interengaging means carried by said sleeve and lower tube section to maintain said sight in predetermined axial and rotational position within said sleeve.

5. The combination as specified in claim 4, an indicator dial rotatable in said housing concentric of said tube sections, and means including said dial operable to rotate said upper section relatively to said lower section about their common axis, to rotate in azimuth the line of sight determined thereby.

6. The combination as specified in claim 4, first and second mutually normal levels carried by said housing, and angularly related link connections, each adjustable in length, connecting said housing to said platform.

'7. A panoramic sight comprising upper and lower tube sections, said upper section being mounted on and rotatable relatively to said lower section about their common longitudinal axes, an entrance reflector pivoted on a normally horizontal axis at the upper end of said upper section, first and second interfitting sleeves journaled within and coaxially of said lower tube section, said first sleeve being rigidly connected with said upper tube section, means on the lower end of said lower section to rotate said first sleeve and upper section, said means including a cupshaped dial 'rigidly attached to the lower end of said first sleeve, a housing for said dial a 90 ocular rigidly carried by the housing below said dial, said housing being fixed to the lower end of said lower tube section and including a radial flange axially spaced above and parallel with said dial, means carried by said housing to axially translate said second sleeve, said last-named means including a threaded collar concentric of said longitudinal axis and rotatably fitting between said flange and dial, means responsive to axial translation of said second sleeve to pivot said entrance reflector, and optical elements within said upper tube section and'second sleeve to focus rays from said entrance reflector axially through said tube sections and dial into said ocular.

8. In a panoramic telescope, a normally vertical lower tube section, an upper tube section pivoted on said lower tube section in axial end-toend alignment therewith, an entrance prism pivoted on a normally horizontal axis at the top of said upper section, a flange having a plane lower surface fixedly carried by the lower end of said lower section, a housing secured to and depending from said flange, an ocular carried by'the lower end of said housing, first and second concentric sleeves rotatably mounted within said lower tube section, a rigid connection between said first sleeve and upper tube section, a cupshaped dial fixed to the lower end of said first sleeve within said housing, azimuth indicator means carried by said housing and cooperable with said dial; means carried by said housing forrotating said dial, first sleeve and upper tube section as a unit, an internally threaded collar journalled within said housing between said plane surface and dial coaxial of said tube sections, a

ring threadedly engaging said collar and mounted for axial translation only, a connection between said ring and second sleeve, means responsive to axial translation of said second sleeve to pivot said prism about its horizontal axis, manually operable means carried by said housing to rotate said collar and thereby axially translate said ring and second sleeve to pivot said prism, and optical means within said tube sections to project rays from said prism axially along said tube sections to said ocular. Y

9. In a periscopic sight, a lower normally vertical tube, having a housing fixed to the lower end of said tube, a first sleevefitting and rotatably mounted within said lower tube coaxially therewith and extending downwardly into said housing, an upper tube fixed to the upper end of said first sleeve in coaxial end-to-end relation therewith and projecting externally of said lower tube, an entrance prism pivoted in the upper end of said upper tube about a normally horizontal axis, an eyepiece carried by said housing, a second sleeve coaxially rotatable within said first sleeve and extending into said housing, optical means including a dove prism fixed in said second sleeve and a second prism fixed in said housing said dove prism and second prism projecting into said eyepiece rays incident on and reflected axially along said tubes by said entrance prism, a circular dial in said housing fixed to said first sleeve coaxially thereof, and a difierential in said housing including av first sun gear fixed to said first sleeve, a second sun gear fixed to said housing, and a planetary gear journaled on said second sleeve and meshing with both said sun gears.

10. The sight recited in claim 9, a third sleeve having a square-cut upper end and journaled between and coaxially with said first and second sleeves, a push rod mounted for axial translation within and along said upper tube and having its lower end resting on the upper end of said third sleeve, means operated by axial translation of said push rod to pivot said entrance prism about its horizontal axis, and manually operable means carried by said lower tube and housing to axially translate said third sleeve and thereby pivot said entrance prism about its normally horizontal axis.

11. The sight recited in claim 10, said last-in- 13 cluded means comprising a fourth sleeve mounted for axial translation only between said lower tube and first sleeve and extending into said housing, a pin fixed to the upper end of said fourth sleeve and engaging an aperture in said third sleeve through a slot in said first sleeve, a threaded collar journaled in said housing, a ring threaded into said collar and fixed to the lower end of said fourth sleeve, means carried by said housing and operable externally thereof to rotate said collar, and means carried by said housing and operable externally thereof to rotate said dial, first sleeve and upper tube as a unit relatively to said lower tube about their common longitudinal axis.

GEORGE RATTRAY.

REFERENCES CITED The following references are of record in the file of this patent:

Number Number 14 UNITED STATES PATENTS Name Date Hahn Dec. 10, 1907 Dawson et al June 20, 1916 Schurmann June 27, 1916 Arms July 25, 1916 Schurmann Sept. 26, 1922 Baroni Apr. 4, 1939 Gunther Dec. 26, 1939 Robinson Nov. 14, 1944 FOREIGN PATENTS Country Date Great Britain Jan. 25, 1929 

